Power brick

ABSTRACT

Briefly, in accordance with one embodiment of the invention, a power brick for use with a network adapter includes: a power supply and at least one signal transformer. The power supply and the signal transformer are physically remote from the network adapter and capable of being electronically coupled to the network adapter via a cable.  
     Briefly, in accordance with another embodiment of the invention, a power brick for use with a network adapter includes: at least two signal transformers. The at least two signal transformers are physically remote from the network adapter and capable of being electronically coupled to the network adapter via a cable.  
     Briefly, in accordance with one more embodiment of the invention, a method of using a power brick with a network adapter includes the following. A high voltage power signal including superpositioned high frequency communications signals is received via a power brick. The voltage of the received signal is reduced. The reduced voltage signal is transmitted to the network adapter via a cable.

BACKGROUND

[0001] 1. Field

[0002] The present invention relates to a network adapters and, moreparticularly, to network signaling through a power brick.

[0003] 2. Background Information

[0004] Due at least in part to the electrical coupling between remotelocations, such as homes and businesses, via power lines, it may bedesirable to use such power lines to also transmit communicationsignals. For example, a local area network (LAN) or other type ofcomputer network may communicate via such power lines. One difficulty,however, of employing this approach relates to accommodating circuitryfor sending and receiving signals via these power lines, while alsousing the power lines as a power source. Adaptive Networks of Newton,Mass., for example, employs a network adapter housing and a conventionalpower cord or cable that couples the adapter housing to a wall outlet.Adaptive Networks has a website on the World Wide Web at the URL,http://www.adaptivenetworks.com/. Within this network adapter housing isincorporated a direct current (DC) power supply andcapacitor/transformer circuitry to transmit and receive communicationssignals via the power lines. Due, at least in part, to the unusual useof the power lines as a communications medium, a need exists for anapparatus or configuration that efficiently and effectively addressesthe complexities of combining electrical circuitry to accomplish thesemultiple goals.

SUMMARY

[0005] Briefly, in accordance with one embodiment of the invention, apower brick for use with a network adapter includes: a power supply andat least one signal transformer. The power supply and the at least onesignal transformer are physically remote from the network adapter andcapable of being electronically coupled to the network adapter via acable.

[0006] Briefly, in accordance with another embodiment of the invention,a power brick for use with a network adapter includes: at least twosignal transformers. The at least two signal transformers are physicallyremote from the network adapter and capable of being electronicallycoupled to the network adapter via a cable.

[0007] Briefly, in accordance with one more embodiment of the invention,a method of using a power brick with a network adapter includes thefollowing. A high voltage power signal including superpositioned highfrequency communications signals is received via a power brick. Thevoltage of the received signal is reduced. The reduced voltage signal istransmitted to the network adapter via a cable.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The subject matter regarded as the invention is particularlypointed out and distinctly claimed in the concluding portion of thespecification. The invention, however, both as to organization andmethod of operation, together with objects, features, and advantagesthereof, may best be understood by reference to the following detaileddescription when read with the accompanying drawings in which:

[0009]FIG. 1 is a schematic diagram illustrating an embodiment of apower brick in accordance with the present invention; and

[0010]FIG. 2 is a schematic diagram illustrating another embodiment of apower brick in accordance with the present invention.

DETAILED DESCRIPTION

[0011] In the following detailed description, numerous specific detailsare set forth in order to provide a thorough understanding of theinvention. However, it will be understood by those skilled in the artthat the present invention may be practiced without these specificdetails. In other instances, well-known methods, procedures, componentsand circuits have not been described in detail so as not to obscure thepresent invention.

[0012] As previously indicated, in some instances it may be desirable totransmit communication signals using power lines. In one approach, thesecommunication signals are superimposed upon or superpositioned with thealternating current (AC) high voltage signals transmitted via the powerline. Thus, special circuitry is employed to transfer signals andreceive signals via the power lines that are also employed to transmitpower. By employing the power lines in this manner, it may be possibleto have a local area network (LAN) or other type of computer network inwhich the computers are mutually coupled and communicating using thesepower lines. Of course, as is well-known, typically personal computers(PCs) operate using relatively low voltage direct current (DC) powersources, whereas power lines typically act as a source for high voltagealternating current (AC) power signals. Therefore, complexities mayarise in accommodating the electrical circuitry to address both the lowvoltage direct current (DC) needs of a personal computer, while alsoaccommodating the high voltage alternating current (AC) power deliveredvia the power lines. In one approach, a company, Adaptive Networks,provides a network adapter housing that incorporates both a low power DCpower supply and capacitor/transformer circuitry used to transmit andreceive high frequency signals via the power lines. Although such anapproach may provide satisfactory operation, it does have disadvantages.For example, the network adapter housing is enlarged to provide adequatephysical space for the additional electrical circuitry, in comparisonwith typical network adapters for PCs. Likewise, to provide the highvoltage alternating current (AC) power from the wall outlet to theadapter housing, a conventional power cord several feet in length isemployed and routed adjacent to the networked (low power) PC. Aside frombeing bulky, this approach may be disadvantageous from a safetystandpoint due to the presence of the high voltage alternating current(AC) signal and may therefore make it difficult to obtain safetycertification for such an arrangement.

[0013]FIG. 1 is a schematic diagram illustrating an embodiment 150 of apower brick for use with a network adapter, such as adapter 130illustrated also in FIG. 1. In this context, the term power brick refersto an enclosure containing an AC-to-DC power supply converter. Brick 150and adapter 130, coupled via cable 140, comprise an embodiment of asystem for coupling a PC to a network using power lines. As illustrated,in this particular embodiment, brick 150 includes power supply 160,signal transformer 170 and signal transformer 180. Also included in thisembodiment are capacitors 10, 20, 30 and 40 and resistors 50 and 60. Asillustrate DC power supply 160 is coupled to the power lines to receiveAC power via three couplings. In this embodiment, one coupling iscoupled to electrical ground, one coupling is coupled to neutral, andone coupling is coupled to the alternating current (AC) plug line, whichin this particular embodiment, provides 120 volts AC. Likewise, in thisparticular embodiment, power supply 160 converts the 120 volts AC to 5volts DC, although, of course, the invention is not limited in scope tothese particular AC and DC voltage levels. In this particularembodiment, DC power supply 160 provides five volts DC to powercircuitry 110. Also, in this particular embodiment, circuitry 110 iscoupled to a parallel port of a personal computer via a cable.Therefore, circuitry 110 receives the digital signals from physicalinterface device 120 that have been produced based, at least in part, onthe analog signals received via the power lines. Circuitry 110 producesdigital signals in an appropriate format for communication with the PC.Likewise, digital signals are received from the PC in this format andconverted to digital signals to which physical interface device 120 willrespond so that analog signals, based, at least in part, on the digitalsignals applied to device 120, are transmitted via the power lines. Ofcourse, in an alternative embodiment, the PC may couple to the networkadapter through a serial port instead of a parallel port.

[0014] As FIG. 1 illustrates, in this embodiment, circuitry to the leftof cable 140 comprises low voltage circuitry, whereas high voltagecircuitry is provided to the right of cable 140. More specifically, aspreviously described, circuitry 110 operates using 5 volts DC power inthis embodiment. Likewise, physical interface device 120 comprises a lowvoltage device and receives signals that have been electromagneticallyinduced by at least one of transformers 170 and 180 in this embodiment.These low voltage signals are transmitted to and from physical interfacedevice 120 via at least one of two twisted pairs of wires included incable 140, in this particular embodiment. This embodiment includesadditional transformers 175 and 185 to improve signal quality, althoughthese may be omitted in other embodiments. These low voltage signals arethen superimposed on the power lines or superpositioned with the powersignals by at least one of the transformers in brick 150, again throughelectromagnetic induction. Further, high frequency signals received viathe power lines induce electromagnetic signals to be communicated tophysical interface device 120 via at least one of two twisted pairs ofwires in cable 140, in this embodiment. As illustrated, capacitors 10through 40 are employed to filter out direct current (DC) or lowfrequency components and shunt resistors 50 and 60 are included to matchthe impedance of one cable and, thereby, improve signal quality on thetwisted pair wires.

[0015] An advantage, then, of this particular approach is that the highvoltage circuitry employed for communicating high frequency signals viathe power line and for providing power are physically removed from orphysically remote from the network adapter which, in this particularembodiment, only includes low voltage circuitry. Therefore, thisapproach is both safe, from a PC user perspective, by physicallyisolating the high voltage circuitry and, likewise, as a result, iseasier to certify for safety (e.g., Underwriters Laboratory). Inaddition, a housing for the network adapter may employ standard housing,thereby reducing or eliminating the need to manufacture specialcomponents for this networking approach, other than manufacture ofthe-power brick itself. This may reduce manufacturing costs.Furthermore, cable 140, which comprises twisted pairs of wires, is bothsafer and more desirable than a conventional power cord.

[0016]FIG. 2 is a schematic diagram illustrating another embodiment 250of a power brick, as well as an embodiment 230 of a network adapter andanother embodiment 240 of a cable comprising twisted pairs. Althoughsimilar to the embodiment illustrated in FIG. 1, this particularembodiment provides an advantage in that this power brick employs lesscircuitry than the embodiment of FIG. 1. As shown, a DC power supply isnot provided. Nonetheless, this particular embodiment provides similaradvantages to the embodiment of FIG. 1, such as: separating high voltageand low voltage circuitry physically, being relatively easy tomanufacture, and providing improved safety, ease of safetycertification, and simplification of the coupling cable. In thisparticular embodiment, circuitry, such as 210 in FIG. 2, is powered viathe PC itself, instead of from the power lines circuitry,. Such anapproach may be employed where signaling specifications, such as PCI or1394, for example, are employed, which describe providing low voltagepower to such circuits. Therefore, in this particular embodiment,although the invention is not limited in scope in this respect, a PCIspecification compliant bus couples circuitry 210 to the PC. As aresult, therefore, cable 240 comprises two twisted pairs, in comparisonwith cable 140 of FIG. 1, in which three are employed.

[0017] More information about the Peripheral Component Interconnect(PCI) Specification is available from PCI Special Interest Group, 2575NE Kathryn St., #17, Hillsboro, Oreg. 97124. More information aboutIEEE's 1394 Specification is available from the 1394 Trade Associationhaving a website on the world wide web at URL http://firewire.org/ orfrom the IEEE at 445 Hoes Lane, Piscataway, N.J.

[0018] An embodiment of the method of using a power brick and a networkadapter in accordance with the present invention, such as theembodiments of a power brick and a network adapter previously described,may include the following. A high voltage power signal includingsuperpositioned high frequency communications signals may be receivedvia a power brick, such as, for example, illustrated in FIG. 1, in whichhigh voltage power signals are received by power brick. Within the powerbrick in the particular embodiment, the voltage of the received powersignals is reduced. For example, as illustrated in FIG. 1, at least oneof the two transformers 170 and 180 is employed with capacitors toreduce the voltage of the received signal by filtering the high voltage,low frequency component of the received signal. For example, in thisembodiment, a 120 V, 50-60 Hz component is filtered out. Then, thereduced voltage signal is transmitted to the network adapter via acable, such as in FIG. 1 via cable 140 to network adapter 130. Asillustrated in FIG. 1, the cable, such as cable 140, may comprise a lowvoltage cable. Furthermore, in the network adapter, 130 in thisparticular embodiment, the high frequency communications signals thathave been passed are then converted to digital signals, such as byphysical interface device 120 in FIG. 1. The digital signals are thentransmitted to a PC coupled to the network adapter. For example, asillustrated in FIG. 1, the digital signals are transmitted to digitalcircuits 110 for formatting and then transmitted via a parallel portcable to a PC. It will, of course, be appreciated that the invention isnot limited in scope to this particular embodiment and manymodifications and variations are possible. Likewise, as illustrated inFIG. 2, a PCI specification compliant bus connection to the PC may beemployed. Of course, again, the invention is not limited in scope inthis respect.

[0019] While certain features of the invention have been illustrated anddescribe herein, many modifications, substitutions, changes andequivalents, will now occur to those skilled in the art. It is,therefore, to be understood that the appended claims are intended tocover all such modifications and changes as fall within the true spiritof the invention.

1. A power brick for use with a network adapter comprising: a powersupply and at least one signal transformer; said power supply and the atleast one signal transformer being physically remote from said networkadapter and being capable of being electronically coupled to saidnetwork adapter via a cable.
 2. The power brick of claim 1 , whereinsaid brick is adapted to be coupled to conventional power lines andwherein said power supply is adapted to convert AC power to DC power. 3.The power brick of claim 2 , and further including another signaltransformer, the two signal transformers being coupled in aconfiguration to send and receive high frequency communication signalsvia said conventional power lines.
 4. The power brick of claim 3 ,wherein said network adapter includes circuitry to format digitalsignals for communication with a PC via a cable coupling to a parallelport of the PC.
 5. The power brick of claim 1 , wherein said cablescomprises low voltage cables.
 6. A method of using a power brick with anetwork adapter comprising: receiving via said power brick high voltagepower signals including superpositioned high frequency communicationssignals; reducing the voltage of the received signals; and transmittingthe reduced voltage signals to the network adapter via a cable.
 7. Themethod of claim 6 , wherein said cable comprises a low voltage cable. 8.The method of claim 6 , and further comprising: converting the highfrequency communication signals to digital signals.
 9. The methods ofclaim 8 and further comprising: transmitting the digital signals to a PCcoupled to said network adapter.
 10. A power brick for use with anetwork adapter comprising: at least two signal transformers; said atleast two signal transformer transformers being physically remote fromsaid network adapter and being capable of being electronically coupledto said network adapter via a cable.
 11. The power brick of claim 10 ,wherein said cable comprises a low-voltage cable.
 12. The power brick ofclaim 10 , wherein said brick is adapted to be coupled to conventionalpower lines.
 13. The power brick of claim 12 , wherein said at least twosignal transformers are coupled in a configuration to send and receivehigh frequency communication signals via said conventional power lines.14. The power brick of claim 13 , wherein said network adapter includescircuitry to format digital signals for communication with a PC via acable coupling to a parallel port of the PC.